Method and apparatus for suction unloading of sand barges



Jul 4, 1967 METHOD AN J. DE KONING 3,329,287

D APPARATUS FOR SUCTION UNLOADING 0F SAND BARGES Filed April 3, 1965 3Sheets-Sheet 1.

(PRIOR ART) IN VENTOR JAN de KoNi/vc:

BY Mvyg ATTORNEY$ July 4, 1967 J. DE KONING 3,329,287

METHOD AND APPARATUS FOR SUCTION UNLOADING OF SAND BARGES Filed April 5,1965 5 Sheets-Sheet FIGS J'AN dc /(ONI'NG- BY 1M ATTORNEYS July 4, 1967METHOD AND J. DE'KONING 3,329,287 APPARATUS FOR SUCTION UNLOADING OFSAND BARGES:

Filed April 5, 1965 3 Sheets-Sheet, F

INVENTOR JA N de KoNiNG ATTORNEYS United States Patent 3,329,287 METHODAND APPARATUS FOR SUCTION UNLOADING 0F SAND BARGES Jan de Koning,Amsterdam, Netherlands, assignor to N.V.

Ingenieursburean voor Systemen en Octrooien Spanstaal, Rotterdam,Netherlands, a Dutch manufacturing company Filed Apr. 5, 1965, Ser. No.445,395 Claims priority, application Netherlands, Apr. 7, 1964,6,403,663 6 Claims. (Cl. 214-14) This invention relates to a method ofsuction-unloading at least one floating barge filled with sand or someother type of spoil, a washing medium being introduced into the bargeand sand together with said washing medium being pumped as a suspensionout of the barge to the required destination by means of at least onesuction nozzle, the barge being displaced with respect to the suctionnozzle during suction-unloading.

In this known method it is inevitable that some of the sand initially infront of the suction nozzle will subsequently be spilt behind thenozzle. In the known method this spilt sand or spillage is washed backtowards the suction nozzle with excess water and then sucked in by thenozzle together with the excess water. In this way the barge is alwayscompletely or substantially completely unloaded, while the suctionnozzle is situated some dis tance away from the gap in the sand toenable the excess water and spilt sand to slow to a position in front ofthe suction nozzle. I propose to continuously keep the suction nozzleclose to the gap in the sand and to move the barge continuously withrespect to the suction nozzle during suction-unloading. This gives insome circumstances outstanding advantages despite the fact that thespilt sand remains in the barge. The present invention provides a stillfurther developed method, which has the advantage that the suspensiondrawn in by the nozzle has a high sand concentration, while the barge isnevertheless completely or substantially completely emptied, this effectbeing achieved by the fact that a first part of the sand is pumped outof the barge to its destination in the form of a suspension having ahigh sand concentration, by means of a first suction nozzle, and theremainder of the sand is conveyed to a position near the first suctionnozzle by means of a second suction nozzle.

According to the present invention, the spilt sand which remains in thebarge in the method according to the abovementioned proposal, cannevertheless be sucked in, so that the method can be advantageouslyapplied in every case, i.e., even if the distance covered by the bargesis considerable.

Preferably, during the period when the first part of the sand present inthe barge is being sucked in by means of the first suction nozzle, theremainder of the sand in the same barge is being conveyed to theposition near the first suction nozzle by means of the second suctionnozzle.

When a number of full barges are being successively suction-unloaded, itis preferable for the first part of the sand to be pumped from aspecific barge to its destination by means of the first suction nozzleas hereinbefore described, and then for the remainder to be deliveredfrom said barge to the next barge in the form of a washing medium whilethe first part of the sand from the next barge is being pumped to itsdestination in the form of a high-concentration suspension.

3,329,287 Patented July 4, 1967 Very fast operation is obtained by thealternate application of the two methods proposed in the preceding twoparagraphs. The barges can then be continuously completely emptied bysuction successively with very short change-over times.

The invention also covers the novel suction-unloading installationspecially adapted to the method of the invention.

It should be pointed out that Dutch patent specification No. 96,078describes a completely dilferent method of obtaining sand orsuction-unloading sand-filled barges, wherein in order to obtain ahigh-concentration suspension in a delivery pipe a single suction nozzledraws in a suspension having a low sand concentration, the suspension ispumped into a large settling tank constructed in the form of an overflowtank, a high-concentration suspension is pumped from the bottom of thelarge settling tank into a delivery pipe, while the suspensioncontaining a low sand concentration, which has overflowed from the largesettling tank to a smaller tank, is pumped back to a position near thesuction nozzle. The high sand concentration of the suspension which itis required to pump into the delivery pipe is controlled by pumping aquantity of suspension out of the smaller tank into the bottom of thelarge settling tank. This known method is very complicated and inaddition to four sand pumps requires two tanks, one of which is ofenormous dimensions.

The invention will be explained with reference to the drawing in thefollowing description, which includes additional features to thosealready mentioned.

In the drawing:

FIG. 1 is a diagrammatic top plan viiew of a barge suction-unloader,showing the known method in which a barge moving alongside thesuction-unloader is unloaded;

FIG. 2 is a cross-section on the line I'III in FIG. 1, thesuction-unloader being omitted;

FIG. 3 is a similar cross-section to FIG. 2, showing the first step ofthe method according to this invention;

FIG. 4 is a similar cross-section to FIG. 2, showing the use of anothermethod according to the invention;

FIGS. 5 and 6 are diagrammatic top plan views of a suction-unloadinginstallation for the simultaneous unloading of two barges in accordancewith two variants of the method according to the invention;

FIGS. 7 and 8 are diagrammatic top plan views of a suction-unloadinginstallation for the simultaneous unloading of two barges according toanother variant of the method according to the invention, the valves inthe two figures being shown in different positions;

FIG. 9 is a partial cross-section through a barge unloaded by suctionaccording to yet another variant of the method according to theinvention.

In the known method illustrated in FIGS. 1 and 2, a suction unloader 1comprising two water pipes 4 and 5 fed by a water pump 19, a nozzle 2 atthe end of a suction pipe 3, and a sand pump 20 connected to the suctionpipe 3, draws the sand from a barge 6 and conveys it to its destinationvia a delivery pipe 21 connected to the sand pump 20.

During suction unloading, the barge 6 is hauled successive distances inthe direction of the arrow 11 through the agency of a cable 8 which ispartly wound on a driven winch 7 and which runs via a guide sheave 9 onthe suction unloader to a bollard 10 on the barge, the mooring line 12securing the barge 6 to the suction unloader 1 being paid outsuccessively.

When a barge 6 filled with solid sand 13 has tied up along the suctionunloader 1, the sand situated in the forepart of the barge is loosenedwith water from the water pipe 4 .and then the suction nozzle 2 islowered into the loosened sand. While this sand is sucked in togetherwith the water from the pipe 4, the nozzle 2 continuously descends asfar as the bottom of the barge 6 where it sucks away the surroundingsand for some time. The sand sticking to the forepart edge 17 of thebarge 6 is then washed towards the nozzle 2 by means of water from thepipe -5. During this process, an increasing amount of sand arrives fromthe gap which has formed on the right of the suction nozzle in FIG. 1.This sand is taken up by the suspension 16 surrounding the suctionnozzle. The said gap thus moves continuously away from the nozzle 2. Assoon as the forepart of the barge 6 has been emptied, the barge 6 ishauled along in the direction of the arrow '11 so that after suchoperation the suction nozzle is at a smaller distance from the gap. Aconcave ap 14 thus forms after a number of hauling operations, as showin FIGS. 1 and 2.

When the sand 15 adhering to the sides drops down, most of it willassume a position behind the suction nozzle 2 in the form of spillagesand 18. As the suction nozzle 2 increasingly approaches the gap 14,there will of course be an increasing amount of spillage 18. The suctionnozzle 2 is therefore kept a considerable distance away from the gap 14.Also, the spillage 18 can readily be washed to a position in front ofthe nozzle 2 by means of water from the pipe 5. As a result of thissystem, the suspension 16 in front of the nozzle has a relatively lowsand concentration. The extraction of the last remnant of sand from thebarge 6, in particular, is at the expense of a very low sandconcentration in the extracted suspension.

As shown in FIG. 3, with the method according .to the invention, thenozzle 2 is held close to the gap 14. The barge 6 is hauled continuouslyin order continuously to follow the gap 14 despite the fact that sand iscontinuously being sucked from and out of said gap, so that thesuspension drawn in continuously has a high sand concentration. As aresult of this new method there is a considerably larger amount ofspillage 18 behind the suction nozzle 2, but such spillage is not washedback with excess water as in the known method. In many cases, moreparticularly when the barge 6 is filled with fine sand and the bargeroute is relatively short, it is more economic to leave the spilt sandin the barge 6 and return the barge only partly unloaded to the dredgingsite, than to transport the sand through the delivery pipe with anexcess of water at the expense of a considerable power loss. Preferably,however, as shown in FIGURE 4, the barge is in any case not returned tothe dredging site only partly unloaded. The spilt sand 18 can in fact bevery elegantly removed from the barge by sucking the same up as asuspension with, if necessary, a low concentration, by means of a secondsuction nozzle 22, and conveying it to close to the first suction nozzle2 by means of a second sand pump 23 and a pipe 24.

This first suction nozzle 2 and the second suction nozzle 22 may belocated in the same barge 1 as shown in FIG- URE 4 or the first suctionnozzle 2a may be located in the one and the second suction nozzle 22a inthe other of two barges described in connection with FIGURES through 8.In addition to being conveyed directly to a position close to the firstsuction nozzle, the spilt sand can be so conveyed indirectly, forexample via the slope of the solid sand. In this way the suspension actsas a washing medium and the water supply via the pipe 4 can be reducedor stopped. In this way a high sand concentration is obtained in frontof the sand suction nozzle 2. The pipe 3 should be of a length such thatany overflow from the suction pipe or the sand pump 20 in conjunctionwith the vacuum and the required concentration are at the correct levelso that the required concentration cannot be exceeded.

The floating suction unloader 1a illustrated in FIG. 5 is intended forthe performance of a more developed method according to the inventionand is completed by a spud barge 25 both ahead and astern. Two mooringstages are thus provided for the barges 6a and 6b. Apart from the usualsand pump 20a, which pumps the sand to its destination by means of thesuction nozzle 2a, suction pipe 3a containing the valve 29, and thedelivery pipe 21a, and the usual water pump 19a which, when the valves26, 27 and 28 are open can pump Water to the delivery pipe 21a, waterpipe 5a and water pipe 5b respectively, the suction unloader 1a alsoincludes a second sand pump 23a which can convey a suspension of waterand sand from the barge 6b to the barge 6a by means of the secondsuction nozzle 22a and the pipe 24a.

The barges are unloaded by suction as follows: firstly, barge 6b is tiedup to the suction unloader 1a in the position of barge 6a beneath thesuction nozzle 2a and valve 27 is opened while water is pumped into thebarge to act as a washing medium. The suction nozzle 2a is then loweredinto the barge 6b, which is partly emptied as described in connectionwith FIG. 3, so that the spilt sand 18 remains in the barge because ofthe continuous dis placement of barge 6b with respect to nozzle 2a. Thebarge 6b and the still completely full barge 6a are subsequently tied upin the positions shown in FIG. 5 and respectively beneath the second andfirst suction nozzles 22a and 2a. During this change of the barges,valve 29 is closed and valve 26 is opened to deliver water in thedelivery pipe 21a to maintain conveyance in said pipe. After the bargeshave been changed over, valve 28 is opened to supply water to barge 6b,the spillage sand 18 is delivered to barge 6a by means of the secondsuction nozzle 22a, pump 23a and pipe 24a, and the sand from barge 6a ispumped to its destination, through the agency of nozzle 2a, suction pipe3a, sand pump 20a and delivery pipe 21a, in the form of ahigh-concentration suspension, by the barges 6b and 6a being moved at aspeed such that the suction nozzle 2a is continuously situated in ahigh-concentration suspen- SlOIl.

Of course the barge 6b must be moved at a constant speed if the barges6a and 6b are situated fairly close together, to avoid obstruction ofbarge 6a by barge 6b. To this end, the two barges may for example besecured to a single haulage system. If desired, the suction nozzles 2aand 22a may be disposed far apart or on either side of the suctionunloader if the barges 6a and 6b are required to be displaced atindependent speeds.

When the furthest left portion of the barge 6a with reference to FIG. 5has arrived at the nozzle 2a, a certain quantity of spilt sand 18 willbe left in this barge, while the barge 6b is practically completelyempty. Finally, barge 6b can disappear and barge 6a occupy its position,whereupon the process can be continuously repeated with other filledbarges 6.

In FIG. 6, the suction unloader 1a is situated in the Water at such adistance from the quay that barges 6 can be tied up on each side. Infact four mooring stations 32 are thus created for barges 6, stations32a and 32a being the same in principle as station 32a, while stations32b and 32b" are the same as station 32b in FIG. 5. With the valves 29'and 29" open, the sand pump 20a and the suction nozzles 2a and 2a"respectively can draw sand in a high concentration from the barges 6 atthe respective stations 32a and 32a", while in the latter barges, withthe valves 30a and 30a" respectively open, and depending upon whetherthe valves 30b and 30b" are open or closed, washing water together withspillage sand can be conveyed out of the barges 6 at the respectivestations 32b and 32b by means of the said pump 23a and the respectivenozzles 22a and 22a".

The spillage sand may or may not be pumped over crosswise.

An advantage of the suction unloader according to FIG.

6 is that during unloading of a still completely full barge and a bargefilled with spillage sand at two of the four moorin stations, the barges6 at the other mooring stations can be changed over so that a suctionnozzle 2a and a sand suction nozzle 2b are always drawing sand. Withthis system of changing over the barges, no water without sand has to bepumped into the delivery pipe 21b during the barge changeover.

The suction unloader shown in FIGS. 7 and 8 has a mooring station 320 oneach side, such station being arranged in the same way as station 32 inFIG. 5. The connection of the sand suction nozzles 2c, sand pumps 200,water pump 19c, pipes 240 and delivery pipe 21 is variable through theagency of a number of valves, as shown in FIGS. 7 and 8.

For the sake of clarity, the connecting pipe between the water pipe 19and the sand pumps 20c has been omitted from these two figures.

The identical sand pumps 20c are each driven by a separate electricmotor (not shown), the two motors being supplied with current by asingle generator (not shown).

When the valves are in the position shown in FIG. 7, water is pumpedinto the barge 6c filled with spillage sand, the spillage sand isdelivered out of this barge into the sand-filled barge 60 through theagency of nozzle 22c", sand pump 20c" and pipe 240', sand pump 20" andpipe 24c, and a suspension containing a high concentration of sand istransported to its destination from the barge 6c through the agency ofthe nozzle 20', sand pump 20c and delivery pipe 21c, while the twobarges are being hauled along. When barge 6c contains only spillage sandand the empty barge 6c has been replaced by a completely full barge 6d,the functions of the suction nozzles and sand pumps are changed over byadjusting the valves to the positions shown in FIG. 8, water now beingdelivered from pipe 40 into the barge 6c, the spillage sand beingdelivered out of this barge into barge 6d through the agency of thesuction nozzle 22c, sand pump 20c and pipe 240", and a suspensioncontain-ing a high concentration of sand being again delivered to itsdestination through the agency of the suction nozzle 2c", sand pump 20c"and delivery pipe 210.

The pipe 24 leading from the second suction nozzle 22 to the firstsuction nozzle 2 need not necessarily contain a sand pump 23. If thesecond suction nozzle 22d has its pipe 24d connected to the firstsuction nozzle 2d (see FIG. 9), the normal sand pump 20 will draw in aconsiderable amount of sand through the first suction nozzle 2d and arelatively considerable amount of water through the second nozzle 22d.If the barge 6 is drawn along too rapid- 1y, a large plug of sand willform in the first nozzle 2d so that the resistance in the latterincreases and more suspension is drawn in by the second nozzle 22d. Thissuspension containing a relatively low concentration of sand thendissolves sand from the top part of the first suction nozzle 2d. If theratio of the resistances in the first suction nozzle 2d and the pipe24d, and the exact speed of haulage of the barges are respectivelysuitably chosen, an optimum sand concentration can be obtained in thesuspension conveyed by the delivery pipe 21. For simple control of thelatter ratio, for example, a valve 31 may be provided in pipe 24d and/or in the first suction nozzle 2d. A suitable place for this valve 31is, for example, the

point of conection of the pipe 24d and the first suction nozzle 2d.

An advantageous continuous suction process is possible if a number ofbarges 6 is hauled along in the same direction with respect to the twoconsecutive suction nozzles 2 and 22. After a certain time, the positionshown in FIG. 4 will occur, in which the two suction nozzles 2 and 22are inserted into the same barge 6. Some time later, after the suctionnozzle 2 has reached the end of the barge 6 but has not necessarily rundry, said suction nozzle 2 is immediately transferred to the next barge6' which is in the ready position astern the barge 6, while the suctionnozzle 22 remains in the barge 6 to suck up the spillage sand 18. Theend of the pipe 24 is then also held over the barge 6' so that thespillage sand can be injected into barge 6 from barge 6 in the form of asuspension.

After insertion of the suction nozzle 2, barge 6' can immediately behauled along with respect to this nozzle, because the sand sticking tothe leading edge 17 behind the nozzle 2 is sucked in by the secondsuction nozzle which is subsequently introduced into the barge 6'. Itwill be apparent that by successively unloading a number of barges 6 bysuction in the above described manner a continuous suction process isobtained in which the barge changeover times are zero and the suspensiondrawn in by the first suction nozzle 2 continuously has a highconcentration of sand, because said suction nozzle 2 is continuously inor close to the full gap 14 in the sand, whlle the barges arenevertheless satisfactorily unloaded because the spillage sand 18 andthe sand sticking to the front and rear walls is sucked in by the secondsuction nozzle 22.

I claim:

1. A method of suction-unloading at least one float ng barge filled withsand or the like, the method comprising the steps of:

introducing a washing medium into the barge;

pumping the sand and the washing medium in suspension from the barge toa desired location by the action of successively employed first andsecond suc tion nozzles;

the barge being advanced with respect to the first suction nozzle inrelation to the progress of the pumping operation;

the initial pumping operation of the first nozzle being of a suspensioncontaining a high ratio of sand to pumping medium; and

further conveying the remaining sand to the location of the first nozzleby actuation of the second nozzle.

2. The method of claim 1, wherein:

the pumping of the sand by action of the first nozzle and the conveyanceof sand to said location by actlon of the second nozzle are carried outcoextensively.

3. A method of suction-unloading a plurality of floating barges filledwith sand or the like, the method comprising the steps of:

introducing a washing medium into an initial barge;

pumping the sand and the washing medium in suspension from the firstbarge to a desired location by action of a first suction nozzle;

introducing a washing medium into the remaining barges in succession;

pumping the sand and the washing medium from the succeeding barges tosaid desired location by action of successively employed suctionnozzles;

the barges being advanced with respect to the said suction nozzles inrelation to the progress of the pumping operation;

the initial pumping operation of the first nozzle of each barge being ofa suspension consisting of a high ratio of sand to pumping medium; and

conveying the remaining sand of each barge to the next succeeding onethereof by the action of a second nozzle.

4. The method of claim 3, wherein:

the actions of the second nozzles are performed simultaneously with theactions of the first nozzles.

5. The method of claim 3, wherein:

the advance of the barges with respect to one another is continuous andis synchronized with the action of the respective suction nozzles.

6. Apparatus for the suction-unloading of floating barges filled withsand or the like, the apparatus comprising:

a washing pump having an inlet connected to a source of washing mediumand an outlet;

a first sand pump having an inlet and an outlet leading to a sandaccumulation region;

a first suction nozzle connected to the inlet of said first sand pump;

a discharge nozzle connected to the outlet of said washing pump anddisposed to direct washing medium against a mass of sand within a bargeat a point adjacent said first suction nozzle;

a second sand pump having an inlet and an outlet; 21 second suctionnozzle connected to the inlet of said second sand pump and disposed todraw sand suspended in washing medium from a barge remote from saidfirst suction nozzle; and

a second discharge nozzle connected to the outlet of said second sandpump and disposed to discharge sand suspended in washing medium againsta mass of sand adjacent said first suction nozzle.

References Cited UNITED STATES PATENTS GERALD M. FORLENZA, PrimaryExaminer.

ROBERT G. SHERIDAN, Examiner.

1. A METHOD OF SUCTION-UNLOADING AT LEAST ONE FLOATING BARGE FILLED WITHSAND OR THE LIKE, THE METHOD COMPRISING THE STEPS OF: INTRODUCING AWASHING MEDIUM INTO THE BARGE; PUMPING THE SAND AND THE WASHING MEDIUMIN SUSPENSION FROM THE BARGE TO A DESIRED LOCATION BY THE ACTION OFSUCCESSIVELY EMPLOYED FIRST AND SECOND SUCTION NOZZLES; THE BARGE BEINGADVANCED WITH RESPECT TO THE FIRST SUCTION NOZZLE IN RELATION TO THEPROGRESS OF THE PUMPING OPERATION; THE INITIAL PUMPING OPERATION OF THEFIRST NOZZLE BEING OF A SUSPENSION CONTAINING A HIGH RATIO OF SAND TOPUMPING MEDIUM; AND FURTHER CONVEYING THE REMAINING SAND TO THE LOCATIONOF THE FIRST NOZZLE BY ACTUATION OF THE SECOND NOZZLE.
 6. APPARATUS FORTHE SUCTION-UNLOADING OF FLOATING BARGES FILLED WITH SAND OR THE LIKE,THE APPARATUS COMPRISING: